Hopper, Paul and Traugott, Elizabeth (1993)

Abstract

This book gives an overview of various grammaticalization phenomena from the viewpoint of
grammaticalization theory. It is argued that grammaticalization is a highly gradual process, changing
slowly but surely the syntactic category of a lexical item along universal (and unidirectional) historical paths, called grammaticalization clines or paths. Different stages of a grammaticalization cline are taken to represent a continuum between syntactic categories; thus, syntactic categories are
conceived of as non-discrete entities (contrasting with common assumptions in generative linguistics).